Upper East Siders can inhale without fear, according to the MTA.

The air quality around the Second Avenue Subway construction site is not toxic, according to the agency’s internal monitoring reports being released for the first time today.

The amount of particles circulating around the $4.4 billion subway extension does not exceed safety standards set by the US Environmental Protection Agency, the MTA found.

Some residents said they have developed coughs because of the construction.

The agency plans to post weekly-air quality reports on its Web site starting today.